/*
 *  IE7 is not supported, but at least let the calculator display in it
 */
#calcWrapper {
    position:absolute;
}
#overlay {
    -ms-filter: progid:DXImageTransform.Microsoft.Alpha(Opacity = 50);
    filter: alpha(opacity = 50);
}
.waiting {
    -ms-filter: progid:DXImageTransform.Microsoft.Alpha(Opacity = 50);
    filter: alpha(opacity = 50);
}